What is the process for applying a realistic texture over an emission object (ex a fluorescent lamp cover)?
Add a texture to control the strength as well.
So you would have a texture for the color and one different for strength.
To further control the strength you can add a math multiply node (or any other math operation you want) before the strength socket.
using the image from the reference:

For even more control you can add a Light path node and make it so that the camera doesn't see a brighter version of the emitter. Use Is Camera Ray, to control the mix between the visible emitter and the one that illuminates objects.

If you want the lights to flicker in animation just add keyframes to the multiply value or to the emission strength.